Assessment of Criteria of Ventricular Late Potential Measurement Using 187-channel Signal-averaged Vector-projected High-resolution Electrocardiograph

Abstract

Purpose : We developed a novel 187-channel signal-averaged vector-projected high-resolution electrocardiograph(SAVP-ECG)for detecting abnormalities in the spatial location of ventricular late potentials (VLP). The Predictor(Corazonix)is a standard system for detecting VLP with a high predictive accuracy in patients with ischemic heart disease. This study was conducted to verify the validity of the criteria for measuring ventricular VLP by SAVP-ECG. Object and method : We consecutively evaluated 615 patients with cardiovascular disease. We examined the VLP index(filtered QRS［f-QRS］, RMS40, LAS)determined by the Predictor and SAVP-ECG. We evaluated the correlation of the VLP index with the prior development of lethal ventricular arrhythmia in 135 patients with ischemic heart disease. Result : The VLP index of the two models showed a significant correlation. The positive standard values of the VLP index by SAVP-ECG were f-QRS ≧ 127msec, RMS40 ＜ 16 μV and LAS ＞ 44msec. The predictive values for lethal ventricular arrhythmia by the Predictor and SAVP-ECG were 84.6％ and 69.2％ for sensitivity, 71.3％ and 67.2％ for specificity, 23.9％ and 18.0％ for positive-predictive value, 97.8％ and 96.5％ for negative-predictive value, and 72.6％ and 67.4％ for predictive accuracy, respectively. Conclusion : Our study showed that there were significant correlations between the indexes(f-QRS, RMS and LAS)using SAVP-ECG and those using Predictor.